Like so many new concepts in urban planning, road diets seem like a great idea at first. And, like so many concepts in urban planning, they tend to generate a lot more criticism once they’re put into place.

The idea of a road diet is simple: to pinpoint streets that have excess capacity and could be narrowed down without significant car congestion, so providing space for other uses, such as sidewalks and bike paths.

It’s also an almost exclusively American concept, which makes sense; while streets in Britain and other European countries aren’t exactly crying out to be narrowed down, on the other side of the Atlantic, the streets seem to be the only thing wider than the country’s waistlines.

The roots of the concept date back to the 1970s, but it only began gaining traction over the past decade, loosely connected with other movements such as smart growth and complete streets.

Planners in the US began studying cases in which city streets had been widened to improve traffic flow for cars. They found that, in most cases, these projects did little to improve traffic flow, while creating an enormous increase in accidents. For instance, a study done in Fort Madison, Iowa, showed that while widening a main road led to a traffic volume increase of 4 per cent, it also increased the accident rate 14 per cent, and the injury rate by 88 per cent.

The obvious response to these findings is, naturally, to slim wider streets back down. But this slimming down can take many forms: widened sidewalks; replacing four-lane highways with three-lane ones, in which the middle lane is for those turning; and separated bike lanes. Last year, urban planner and author Jeff Speck teamed up with animation specialist Spencer Boomhower to create a series of videos showing the many possible forms road diets can take.

How effective has the concept been? In the US, road diets have seen a number of success stories. In New York City, a 2013 study revealed that road diets there had “significant safety benefits”. They’ve seen success on the west coast, too: a pioneer in road diets, San Francisco has implemented 34 road diet projects over the last four decades, with favourable reactions from traffic engineers. Similar projects have also been implemented successfully in nearby Davis, California.

A street in Davis, CA, before its road diet. Image: Transport Observer/Wikimedia Commons.

But though road diets have allowed some cities to slim down their traffic safety problems, others have found that sticking to road diets is harder than sticking to actual diets.

Take Carolina Beach, North Carolina. Back in 2010, planners implemented a road diet on Lake Park Boulevard, one of the city’s main thoroughfares, in a bid to make the city more bike friendly.

But the measure was met by howls of protest. Local businesses complained of decreased sales, and the city’s car traffic during holidays led to increased traffic jams. In 2012, the road diet was reversed.

Down the coast, in Gainesville, Florida, a road diet was adopted in mid-2013 for a wooded stretch of 8th Avenue. Four traffic lanes were reduced to two on a trial basis.

The same street after its road diet. Image: Transport Observer/Wikimedia Commons.

Then there’s Los Angeles, which despite some noble efforts to reverse its car-centric status by expanding its metro system, lives up to its reputation in its efforts to pursue road diets. Back in 2011, an attempt to implement a road diet on Wilbur Avenue, deep in the depths of the suburban San Fernando Valley, was quickly put to sleep after massive neighbourhood outcry.

Though the reasons road diets fail vary city by city, their common underlying cause boils down to political convenience. By their nature, road diets create an immediate inconvenience for drivers – who tend to be more affluent and politically connected; to compensate that, there’s only the long-term promise of creating greater safety, and a more bike and pedestrian friendly urban environment. For local politicians eager for quick victories, this all too often proves to be a toxic combination.

The lesson is clear. Road diets have paid off for some US cities. But for others, powerful political forces and a deeply rooted car culture have made sticking to road diets as difficult as swearing off junk food.

A couple of weeks ago, someone on Twitter asked CityMetric’s editor about the longest possible UK train journey where the stations are all in progressive alphabetical order. Various people made suggestions, but I was intrigued as to what that definitive answer was. Helpfully, National Rail provides a 3,717 page document containing every single timetable in the country, so I got reading!

(Well, actually I let my computer read the raw data in a file provided by ATOC, the Association of Train Operating Companies. Apparently this ‘requires a good level of computer skills’, so I guess I can put that on my CV now.)

Here’s what I learned:

1) The record for stops in progressive alphabetical order within a single journey is: 10

The winner is the weekday 7.42am Arriva Trains Wales service from Bridgend to Aberdare, which stops at the following stations in sequence:

The second longest sequence possible – 8 – overlaps with this. It’s the 22:46pm from Cardiff Central to Treherbert, although at present it’s only scheduled to run from 9-12 April, so you’d better book now to avoid the rush.

Not quite sure what you’ll actually be able to do when you get to Trehafod at half eleven. Maybe the Welsh Mining Experience at Rhondda Heritage Park could arrange a special late night event to celebrate.

There is a chance for a bit of CONTROVERSY with the last one, as you could argue that the final station is actually called London St Pancras. But St Pancras International the ATOC data calls it, so if you disagree you should ring them up and shout very loudly about it, I bet they love it when stuff like that happens.

Alphabetical train journeys not exciting enough for you?

2) The longest sequence of stations with alliterative names: 5

There are two ways to do this:

Ladywell, Lewisham, London Bridge, London Waterloo (East), London Charing Cross – a sequence which is the end/beginning of a couple of routes in South East London.

4) The greatest number of stations you can stop at without changing trains: 50

On a veeeeery slow service that calls at every stop between Crewe and Cardiff Central over the course of 6hr20. Faster, albeit less comprehensive, trains are available.

But if you’re looking for a really long journey, that’s got nothing on:

5) The longest journey you can take on a single National Rail service: 13 hours and 58 minutes.

A sleeper service that leaves Inverness at 7.17pm, and arrives at London Euston at 9.15am the next morning. Curiously, the ATOC data appears to claim that it stops at Wembley European Freight Operations Centre, though sadly the National Rail website makes no mention of this once in a lifetime opportunity.

6) The shortest journey you can take on a National Rail service without getting off en route: 2 minutes.

Starting at Wrexham Central, and taking you all the way to Wrexham General, this service is in place for a few days in the last week of March.

7) The shortest complete journey as the crow flies: 0 miles

Because the origin station is the same as the terminating station, i.e. the journey is on a loop.

8) The longest unbroken journey as the crow flies: 505 miles

Taking you all the way from Aberdeen to Penzance – although opportunities to make it have become rarer. The only direct service in the current timetable departs at 8.20am on Saturday 24 March. It stops at 46 stations and takes 13 hours 20 minutes. Thankfully, a trolley service is available.

9) The shortest station names on the network have just 3 letters

Ash, Ayr, Ely, Lee, Lye, Ore, Par, Rye, Wem, and Wye.

There’s also I.B.M., serving an industrial site formerly owned by the tech firm, but the ATOC data includes those full stops so it's not quite as short. Compute that, Deep Blue, you chess twat.

10) The longest station name has 33 letters excluding spaces

Okay, I cheated on this and Googled it – the ATOC data only has space for 26 characters. But for completeness’ sake: it’s Rhoose Cardiff International Airport, with 33 letters.

No, I’m not counting that other, more infamous Welsh one, because it’s listed in the database as Llanfairpwll, which is what it is actually called.

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